I'm working on installing a Merlin II system in my home, I have all the voice terminals and console, but need a few system cards. Looking on eBay, it seems that the card for 4 lines/8 stations, has the same name (408) on both the Merlin II, Legend and Magix. I know that some Merlin II successors stopped using 4 pair for the stations. So I'm searching on ebay, and descriptions are not often the best; is the "408" card for the Merlin II and Merlin Legend interchangeable? Also, is the main carrier, and the extension carrier interchangeable? Thanks for any help.